I am not qualified in medicine, so I use the findings of FMARC (FIFA Medical Assessment and Research Center) and the U.S. Soccer Sports Medicine Committee to understand the risks of any soccer technique. Here is a document that I hope you will use to educate coaches on the progression for teaching heading in soccer.

"I saw a different news item about this topic, too. Remember, that this is a presentation and presentations don't go through the rigor of peer review anywhere near the level of critique of a journal publication. Based on what I've read, my first inkling is that it won't get published. Here are the primary factors that a reviewer has to ask of every paper they review:

History: What do the subjects bring into the study? Don't care how detailed the interviews were, they were asking questions about a lifetime of soccer, heading exposure, injuries. FMARC data shows that players forget about half their injuries from that year. This is about a lifetime. I bet if you surveyed players about how many times they headed the ball during a match vs. what was captured on film the results would be remarkably different. History is a HUGE issue with this project. And I haven't even brought up learning disabilities, alcohol, non-sports head injury, non-head injuries, or drug intake. Plus, players this age paid little attention to concussions when they were half their age, so how many did they have? The only accurate answer is "...that I can recall". Hardly firm data.

Maturation: This is about changes over the course of a study. Not as critical here, but this group is making conclusions about the adult brain based on something that may have happened before the brain had matured.

Testing: Oral interviews using a 'detailed' questionnaire (that from another media outlet). One might wonder about the validity of the Q and A. Were the questions 'leading' the subject on one direction or another? Given the emotions surrounding this topic, this probably needs to be considered.

Instrumentation: MRI is getting very good; a question could be that it is finding variants that have little or no effect. Sort of like the right handed pitcher with a crooked left pinkie; a variant of no consequence.

Statistical Regression: Tendency for extreme scores to migrate toward the mean. Basketball team shoots 75% one game is due for a 25% game soon. Not sure this would be as much of an issue as other topics.

Experimental Mortality: Subjects who are included in the study fail to complete it-they drop out, move, die, get sick or hurt, etc. How were the subjects selected? What were the inclusion and exclusion criteria? Any bias in selection stacks the deck one way or another.

Selection-Maturation Interaction: are subjects selected because they have a tendency to gain (or not to gain) much during the study.

Hawthorne Effect: People behave differently when they know they are being studied. This has been shown to be an issue in concussion research. Mention the word, and people are on edge, so to speak.

Those are just the 'standard' items that can lead to an alternative hypothesis for the results. I haven't even approached the actual data and interpretation of the data. We'll have to wait this one out. Stick with the FMARC data for now. Sorry for going on about the peer review process. But the popular media will run with this without doing due diligence."